1) My 82 733i developed several electrical problems.
Later when I bought an 88 735i I found detailed information on how to repair the relays and fix the cold solder joints.
With my '82, the first challenge was the alternator did not receive 12V, so it didn't charge.
I ran a wire directly from a hot post in the fuse box tray to the back of the alternator. That worked.
Then the two speed electric fan had problems. I ran another wire from the fuse tray to the high temperature sensor on the side of the radiator.
Eventually I had 3 or 4 "hay wires".
2) I want to encourage everyone to take digital photos or make a short video and post it to YouTube with detailed information on how they solved repair problems.